Official fix by Parallels

Update: Parallels has released an official KB with a resolution: http://kb.parallels.com/en/113018. If that does not work, you can try the steps below -- but they should be obsolete.

Workaround without Parallels

Only try the steps below if the above KB doesn't resolve your issue.

A quick fix for now is to change the way DrWeb handles the files that contain scanning errors or processing errors. Edit the file /etc/drweb/drweb_handler.conf and search the following.

ScanningErrors = quarantine
ProcessingErrors = reject

And change it to the following.

ScanningErrors = pass
ProcessingErrors = pass

And restart DrWeb.

~# /etc/init.d/drwebd restart

The problem is caused by an update that was pushed automatically on December 15th. It will be resolved as soon as Parallels has a fix for this, after that the fix is also applied automatically as DrWeb loads it's updates.